<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

</body>
<script>
    var Un;
    (function () {
        var instance;

        Un = function Un() {
            if (instance) {
                return instance;
            }

            instance = this;
            instance.num = 10;
            instance.name = 'lilisi';
        }


    })();

    var a = new Un();
    var b = new Un();
    console.log(a === b);
</script>
</html>